176 research outputs found
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Production of a Ξ° Particle Without an Associated Hyperon in A Ï- -P Collision
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MPI-2: Extending the Message-Passing Interface
This paper describes current activities of the MPI-2 Forum. The MPI - 2 Forum is a group of parallel computer vendors, library writers, and application specialists working together to define a set of extensions to MPI (Message Passing Interface). MPI was defined by the same process and now has many implementations, both vendor- proprietary and publicly available, for a wide variety of parallel computing environments. In this paper we present the salient aspects of the evolving MPI-2 document as it now stands. We discuss proposed extensions and enhancements to MPI in the areas of dynamic process management, one-sided operations, collective operations, new language binding, real-time computing, external interfaces, and miscellaneous topics
Prospects for Pentaquark Searches in Annihilations and Collisions
Recent strong experimental evidence of a narrow exotic S = +1 baryon
resonance, , suggests the existence of other exotic baryons. We
discuss the prospects of confirming earlier experimental evidence of
and the observation of additional hypothetical exotic baryons in
annihilations and collisions at LEP and B Factories
Deathly Drool: Evolutionary and Ecological Basis of Septic Bacteria in Komodo Dragon Mouths
Komodo dragons, the world's largest lizard, dispatch their large ungulate prey by biting and tearing flesh. If a prey escapes, oral bacteria inoculated into the wound reputedly induce a sepsis that augments later prey capture by the same or other lizards. However, the ecological and evolutionary basis of sepsis in Komodo prey acquisition is controversial. Two models have been proposed. The âbacteria as venomâ model postulates that the oral flora directly benefits the lizard in prey capture irrespective of any benefit to the bacteria. The âpassive acquisitionâ model is that the oral flora of lizards reflects the bacteria found in carrion and sick prey, with no relevance to the ability to induce sepsis in subsequent prey. A third model is proposed and analyzed here, the âlizard-lizard epidemicâ model. In this model, bacteria are spread indirectly from one lizard mouth to another. Prey escaping an initial attack act as vectors in infecting new lizards. This model requires specific life history characteristics and ways to refute the model based on these characteristics are proposed and tested. Dragon life histories (some details of which are reported here) prove remarkably consistent with the model, especially that multiple, unrelated lizards feed communally on large carcasses and that escaping, wounded prey are ultimately fed on by other lizards. The identities and evolutionary histories of bacteria in the oral flora may yield the most useful additional insights for further testing the epidemic model and can now be obtained with new technologies
Moments of inertia, nucleon axial-vector coupling, the {\bf 8}, {\bf 10}, and mass spectrums and the higher SU(3)_f representation mass splittings in the Skyrme model
The broad importance of a recent experimental discovery of pentaquarks
requires more theoretical insight into the structure of higher representation
multiplets. The nucleon axial-vector coupling, moments of inertia, the {\bf 8},
{\bf 10}, , and absolute mass spectra and the
higher SU(3) representation mass splittings for the multiplets ,
, , , , , and are computed in the framework of the minimal extended
Skyrme model by using only one free parameter, i.e., the Skyrme charge . The
analysis presented in this paper represents simple and clear theoretical
estimates, obtained without using any experimental results for higher
(,...) multiplets. The obtained results are in good agreement
with other chiral soliton model approaches that more extensively use
experimental results as inputs.Comment: 22 pages, 12 figures, 9 tables, version accepted in JHE
Antikaon angular distributions in the reaction near the threshold and the parity of the pentaquark
Within spectator model we study the reaction in the threshold energy region. We present the predictions for
the exclusive and inclusive antikaon angular distributions in the laboratory
system for this reaction calculated for two possible parity states of the
resonance at 1.5 and 1.75 GeV beam energies with and without
imposing the relevant kinematical cuts on those parts of the sampled phase
space where contribution from the main background sources associated with the
, production as well as with the
--rescattering in the final state, is expected to be dominant. We show
that under chosen kinematics these distributions are sensitive to the
parity and, therefore, can be used as a filter for the
determination of its parity.Comment: 18 pages, 8 figures; will be published in Phys.Atom.Nucl_4_200
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